Albert campbell



I UNITED STATES PATENT 'FFIcE.

ALBERT CAMPBELL, OF CHICAGO, ILLINOIS.

FUEL.

SPECIFICATION forming part of Letters Patent No. 624,173, dated May 2,1899.

Application filed February 20, 1899. Serial No. 706,192. (No specimensJTo all whom it may concern.-

Be it known that I, ALBERT CAMPBELL, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Fuel; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

The use of coke as a fuel is comparatively limited. In fact, it can beused with advantage and case only in such apparatus in which the fuel isfed and properly spread over the grate-surface by hand. The nature ofthis fuel-namely, its low specific gravity and its jagged and roughsurfaces-renders it unfit for use in general, because it is not what maybe termed self-feeding, the interlocking of and the frictionalresistance to motion between the lumps or pieces being too great to beovercome by the specific gravityof the fuel, which results in theformation of bridges above the zone of combustion and renders almostconstant attention necessary. This is especially the case when coke isused in selffeeding heaters, whether latrobes, steam or hot water, orother self-feeding heaters, the

fuel choking in the hoppers. To remedy this serious objection to coke asa fuel, it has been proposed to comminute the same-1l. a, break it upinto comparatively small pieces, not much larger than ordinary chestnutcoal but this does not in any manner change the nature of the fuel, inthat the surfaces thereof remain jagged and rough, so as to render itsuse undesirable even in heaters having a feedhopp er of comparativelygreat cross-sectional area and of a comparatively small vertical area,as is the case, for instance, in latrobes.

the interlocking of the lumps or pieces, but

also smooth the entire surface thereof, so as to ofier the leastpossible frictional resist ance to motion under their own weight. This Ieffect by abrasion, friction, or attrition in any suitable apparatus, asthe ordinary tumbling-barrel, attrition-mill, orin any other apparatuswhereby the object aimed at can be obtained by abrasion, friction, orattrition, such apparatus being well known and forming no part of thisinvention.

Having thus described my invention, what I claim as new therein, anddesire to secure by Letters Patent, is

An improved fuel, consisting of coke the lumps or pieces of which havesmooth external surfaces, substantially as and for the purpose setforth.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

' ALBERT CAMPBELL.

\Vitnesses:

N. CURTIS LAMMOND, HENRY ORTH, J r.

